Medication review of patients on long-term treatment in general practice in the UK has been reported to be inadequate. Proposals followed suggesting that pharmacists could use their expertise to lead such a medication review in conjunction with the general practitioner. This paper describes the concept of clinical medication review by a pharmacist based in general practice. We describe the development of a method for a structured and systematic process for undertaking such a review in clinics conducted by a pharmacist. The method was developed for a nationally funded study in the UK. We provide a definition of clinical medication review and suggests a structure for the process through data gathering, evaluation and implementation.